Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at

September 29, 1994

Mr. Forrest W. Frazier Plains Resources 1600 Smith Street Houston, TX 77002

This is in response to your August 5 letter, requesting interpretation of the Process Safety Management (PSM) of Highly Hazardous Chemicals (HHCs) standard, 29 CFR 1910.119. Specifically, you requested confirmation that your typical tank battery which is located at various locations throughout the country would not be covered by the PSM standard either because crude oil at these batteries is stored in atmospheric tanks where it is kept below its normal boiling point without benefit of chilling or refrigeration and therefore excepted by 1910.119(a)(1)(ii)(B) or because these batteries are at remote locations and thereby excepted by 1910.119(a)(2)(iii). Your workplace scenario and our reply follow. Please accept our apology for the delay in responding.

Scenario: The purpose of the facility is to collect and separate crude oil, produced water, and in some locations natural gas. The crude oil and water is stored on site typically in tanks greater than 10,000 pounds (4535.9 kg) and the natural gas is flared. Our crude oil would be considered "flammable" according to 1910.1200(c), and is stored in atmospheric tanks without the benefit of chilling or refrigeration. Also, the process of separation is immediately connected and adjacent to the storage tanks.

Reply: The crude oil production process you describe includes the activities of on-site movement, handling, storage and associated transfer. See the definition of process at 1910.119(b). Since this process includes activities in addition to storage and associated transfer, the atmospheric tank exception at 1910.119(a)(1)(ii)(B) does not apply to the aforementioned "typical tank-battery facility."

You did not provide sufficient information to determine whether the "normally unoccupied remote facility" exception at 1910.119(a)(2)(iii) applies to your tank-battery facilities. The two enclosed copies of PSM letters of interpretation previously issued by the Occupational Safety and Health Administration concerning "normally unoccupied remote facilities" are provided to assist you in this determination.

We appreciate your interest in occupational safety and health. If we can be of further assistance, please contact Mr. Ronald Davies of my staff, telephone 202-219-8031, extension 110.


John B. Miles, Jr., Director Directorate of Compliance Programs